This invention relates generally to agricultural apparatus for reducing and mixing crop residue with the soils for expediting the decay thereof while reducing soil erosion and is particularly directed to an integral shredder/plow combination for mixing and burying surface trash.
Minimum tillage and trash farming techniques are increasingly being used by farmers as a means of reducing the amount of time necessary to accomplish field preparation and planting, permitting the farmer to plant more acreage and increasing the efficiency of his operation. Minimum tillage conservation practices also reduce soil erosion caused by wind and water run-off and reduce the number of tractor passes over the tilled land and the costs of fuel associated therewith. Trash farming and minimum tillage practices contemplate leaving vegetational residue on or near the soil surface to check erosion and serve as a mulch for substantially reducing the cultivation process. This involves reducing the trash residue to a size which facilitates its decomposition while maintaining a partial soil cover for the retention of moisture therein and to prevent wind and water run-off. Examples of prior art vegetation cutting implements are described in U.S. Pat. Nos. 2,999,346 and 3,035,393 to Mathews and 4,148,174 to Mathews and Rogers.
This cultivation process makes use of a cutting or shredding device for reducing trash particle size, followed by a plow assembly for mixing the thus reduced trash with the soil for attaining the aforementioned objectives. Initially, this practice required two separate passes over the worked field, the first for reducing the trash and the second for producing the soil-trash mixture. Later attempts sought to reduce the time and expense in such field preparation by installing a shredder device between the plow assembly and the tractor.
This approach generally made use of shredder or chopper implements which incorporated a rotor mounted within an elongated housing propelled by a tractor along an axis perpendicular to the housing. The rotor is provided with blades which sever and reduce vegetation extending from the terrain over which the device moves. The primary shortcoming of this combination is related to the structure of the shredder assembly which is not designed for the high drag forces produced by a plow assembly. The excessive draw bar pull of a plow would typically result in damage to or the destruction of the shredder assembly.
Not only are the high forces associated with the direction of travel of the tractor destructive of the shredder mechanism, but the shredder is also subjected to large side loading due to ground surface contour variations and during turns such as at the edge of the field being worked. While the longitudinal forces tend to damage the shredder's structural frame, the latter side loading forces are generally too much for the shredder's wheel bearings causing their failure. In addition, the high twisting forces encountered during deep plowing operations tends to tear apart and cause the failure of the shredder frame. Finally, coupling these implement assemblies is a somewhat complex task resulting in a cumbersome structure requiring two separate hydraulic take-off systems for the operation of two separate implement transport systems.
Therefore, in view of the above, the present invention is intended to provide an improved shredder/plow combination which requires a single hydraulic take-off system, avoids applying excessive forces to the shredder assembly, and provides improved trash cutting and soil mixing operation.